Actually your problem is because of class loaders as your war file will have different class loader allocated by tomcat so you will not be able to load your properties file from outside of war file.
the file jboss-service.xml residing in jbossweb-tomcat55.sar\META-INF contains two different options as
if you make these values to true then it will tell the jboss that war won't be having different class loaders anymore. But making these values to true is not a good practice
Thank you for your response, -your suggestion did the trick!